This study will investigate weather certain compounds in soybeans (genistein and related isoflavones) can improve bone strength which may reduce the risk of bone fracture in old age. The study will also try to determine how possible bone strengthening effects of these and other dietary factors are influenced by inherited (genetic) disposition. The risk of bone fracture in later life depends very much on how well bones are nurtured during youth and early adulthood when they are built up to their maximum strength. Calcium and vitamin D are very important for achieving the greatest possible bone strength, but additional dietary factors may include isoflavones that are found in many vegetables and plant foods; soybeans are a particularly rich source of such compounds which include genistein. This investigation is designed to investigate whether a genistein-rich concentrate from soybean has beneficial effect on bone at the critical bone-building age and may thus be helpful in preventing bone fractures in old age.